This. My problem isn't that she's black, it's that she's a token special snowflake.
All the other girls are the same height and size with a color palette that follows some natural aesthetic archetype - blue eyed blonde, green eyes black hair and "brown" eyed ginger (turned pink because it's a cartoon for girls and she's the "main" ppg), and then there's… her.
Speaking only about character design, why is she bigger? Why does she have HIPS? It seems like an extremely racist choice not to make her as young and innocent looking as the others. (This is an actual issue that non-retarded people who fight racism talk about: how black girls are always sexualized and never portrayed in the same innocent, delicate light as white girls are)
Then there's the color palette. I get that it's harder to make a black character visually stimulating and still natural since brown skin, black hair and brown eyed isn't a very good choice for obvious reasons, but it feels like instead of trying to work with it they just said "well, we're doing this to appeal to a tumblrtard audience and they like mermaid and unicorns, right? Yeah, those are gonna be get colors. Lavender and bright blue, like a mermaid unicorn!" and called it a day.
They could have gone for yellow for her eyes and clothes, for example, and left her hair black (with dreads maybe?). As she is now, she just looks like some shitty self-insert and not like an official character.